<!DOCTYPE html>
<html>
<head>
	<meta charset="utf-8">
	<title>元素是否显示</title>
	<script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
</head>
<body>
	<div id="app-3">
		<p v-if="seen">现在你看到我了</p>
	</div>
	<script type="text/javascript">
		var app3 = new Vue({
			el:'#app-3',
			data:{
				seen:true
			}
		})
	</script>
</body>
</html>